Add support for list_to_integer/2

libs/estdlib/src/erlang.erl

@@ -52,6 +52,7 @@
     list_to_existing_atom/1,
     list_to_binary/1,
     list_to_integer/1,
+    list_to_integer/2,
     list_to_tuple/1,
     iolist_to_binary/1,
     binary_to_atom/1,
@@ -600,6 +601,19 @@ list_to_binary(_IOList) ->
 list_to_integer(_String) ->
     erlang:nif_error(undefined).
 
+%%-----------------------------------------------------------------------------
+%% @param   String  string to convert to integer
+%% @param   Base  string to convert to integer
+%% @returns an integer value from its string representation
+%% @doc     Convert a string (list of characters) to integer in specified base.
+%% Errors with `badarg' if the string is not a representation of an integer or
+%% the base is out of bounds.
+%% @end
+%%-----------------------------------------------------------------------------
+-spec list_to_integer(String :: string(), Base :: 2..36) -> integer().
+list_to_integer(_String, _Base) ->
+    erlang:nif_error(undefined).
+
 %%-----------------------------------------------------------------------------
 %% @param   List    list to convert to tuple
 %% @returns a tuple with elements of the list

src/libAtomVM/nifs.c

@@ -120,7 +120,7 @@ static term nif_erlang_link(Context *ctx, int argc, term argv[]);
 static term nif_erlang_float_to_binary(Context *ctx, int argc, term argv[]);
 static term nif_erlang_float_to_list(Context *ctx, int argc, term argv[]);
 static term nif_erlang_list_to_binary_1(Context *ctx, int argc, term argv[]);
-static term nif_erlang_list_to_integer_1(Context *ctx, int argc, term argv[]);
+static term nif_erlang_list_to_integer(Context *ctx, int argc, term argv[]);
 static term nif_erlang_list_to_float_1(Context *ctx, int argc, term argv[]);
 static term nif_erlang_list_to_atom_1(Context *ctx, int argc, term argv[]);
 static term nif_erlang_list_to_existing_atom_1(Context *ctx, int argc, term argv[]);
@@ -386,7 +386,7 @@ static const struct Nif list_to_binary_nif =
 static const struct Nif list_to_integer_nif =
 {
     .base.type = NIFFunctionType,
-    .nif_ptr = nif_erlang_list_to_integer_1
+    .nif_ptr = nif_erlang_list_to_integer
 };
 
 static const struct Nif list_to_float_nif =
@@ -2544,9 +2544,30 @@ static term nif_erlang_list_to_binary_1(Context *ctx, int argc, term argv[])
     return bin_res;
 }
 
-static term nif_erlang_list_to_integer_1(Context *ctx, int argc, term argv[])
+static avm_int_t to_digit_index(avm_int_t character)
 {
-    UNUSED(argc);
+    if (character >= '0' && character <= '9') {
+        return character - '0';
+    } else if (character >= 'a' && character <= 'z') {
+        return character - 'a' + 10;
+    } else if (character >= 'A' && character <= 'Z') {
+        return character - 'A' + 10;
+    } else {
+        return -1;
+    }
+}
+
+static term nif_erlang_list_to_integer(Context *ctx, int argc, term argv[])
+{
+    avm_int_t base = 10;
+    if(argc == 2) {
+        term t = argv[1];
+        VALIDATE_VALUE(t, term_is_integer);
+        base = term_to_int(t);
+        if (UNLIKELY(base < 2 || base > 36)) {
+            RAISE_ERROR(BADARG_ATOM);
+        }
+    }
 
     term t = argv[0];
     int64_t acc = 0;
@@ -2565,22 +2586,21 @@ static term nif_erlang_list_to_integer_1(Context *ctx, int argc, term argv[])
 
     while (term_is_nonempty_list(t)) {
         term head = term_get_list_head(t);
-
         VALIDATE_VALUE(head, term_is_integer);
-
         avm_int_t c = term_to_int(head);
 
-        if (UNLIKELY((c < '0') || (c > '9'))) {
+        avm_int_t digit = to_digit_index(c);
+        if(UNLIKELY(digit == -1 || digit >= base)) {
             RAISE_ERROR(BADARG_ATOM);
         }
 
         //TODO: fix this
-        if (acc > INT64_MAX / 10) {
+        if (acc > INT64_MAX / base) {
             // overflow error is not standard, but we need it since we are running on an embedded device
             RAISE_ERROR(OVERFLOW_ATOM);
         }
 
-        acc = (acc * 10) + (c - '0');
+        acc = (acc * base) + digit;
         digits++;
         t = term_get_list_tail(t);
         if (!term_is_list(t)) {

src/libAtomVM/nifs.gperf

@@ -72,6 +72,7 @@ erlang:integer_to_list/2, &integer_to_list_nif
 erlang:link/1, &link_nif
 erlang:list_to_binary/1, &list_to_binary_nif
 erlang:list_to_integer/1, &list_to_integer_nif
+erlang:list_to_integer/2, &list_to_integer_nif
 erlang:list_to_float/1, &list_to_float_nif
 erlang:list_to_tuple/1, &list_to_tuple_nif
 erlang:iolist_size/1, &iolist_size_nif

tests/erlang_tests/test_list_to_integer.erl

@@ -23,10 +23,16 @@
 -export([start/0, sum_integers/2, append_0/1]).
 
 start() ->
-    sum_integers(append_0("10"), "-1") + safe_list_to_integer("--") - safe_list_to_integer(nan) +
-        safe_list_to_integer("+10") - 10 + safe_list_to_integer("-") - 5 + safe_list_to_integer("+") -
-        5 +
-        safe_list_to_integer("") - 5.
+    sum_integers(append_0("10"), "-1") +
+        safe_list_to_integer("--") - 5 +
+        safe_list_to_integer(nan) - 5 +
+        safe_list_to_integer("+10") - 10 +
+        safe_list_to_integer("-") - 5 +
+        safe_list_to_integer("+") - 5 +
+        safe_list_to_integer("") - 5 +
+        safe_list_to_integer("0a", 16) - 10 +
+        safe_list_to_integer("-0a", 16) + 10 +
+        safe_list_to_integer("1010", 2) - 10.
 
 append_0(L) ->
     L ++ "0".
@@ -35,7 +41,9 @@ sum_integers(A, B) ->
     list_to_integer(A) + list_to_integer(B).
 
 safe_list_to_integer(A) ->
-    try list_to_integer(A) of
+    safe_list_to_integer(A, 10).
+safe_list_to_integer(A, Base) ->
+    try list_to_integer(A, Base) of
         AnyValue -> AnyValue
     catch
         error:badarg ->